1. Field of the Invention
The subject invention relates to alignment devices and, more particularly, to devices for aligning an antenna with a satellite.
2. Description of the Invention Background
The advent of the television can be traced as far back to the end of the nineteenth century and beginning of the twentieth century. However, it wasn't until 1923 and 1924, when Vladimir Kosma Zworkykin invented the iconoscope, a device that permitted pictures to be electronically broken down into hundreds of thousands of components for transmission, and the kinescope, a television signal receiver, did the concept of television become a reality. Zworkykin continued to improve those early inventions and television was reportedly first showcased to the world at the 1939 World's Fair in New York, where regular broadcasting began.
Over the years, many improvements to televisions and devices and methods for transmitting and receiving television signals have been made. In the early days of television, signals were transmitted and received through the use of antennas. Signal strength and quality, however, were often dependent upon the geography of the land between the transmitting antenna and the receiving antenna. Although such transmission methods are still in use today, the use of satellites to transmit television signals is becoming more prevalent. Because satellite transmitted signals are not hampered by hills, trees, mountains, etc., such signals typically offer the viewer more viewing options and improved picture quality. Thus, many companies have found offering satellite television services to be very profitable and, therefore, it is anticipated that more and more satellites will be placed in orbit in the years to come. As additional satellites are added, more precise antenna/satellite alignment methods and apparatuses will be required.
Modern digital satellite communication systems typically employ a ground-based transmitter that beams an uplink signal to a satellite positioned in geosynchronous orbit. The satellite relays the signal back to ground-based receivers. Such systems permit the household or business subscribing to the system to receive audio, data and video signals directly from the satellite by means of a relatively small directional receiver antenna. Such antennas are commonly affixed to the roof or wall of the subscriber's residence or mast located in the subscriber's yard. A typical antenna constructed to receive satellite signals comprises a dish-shaped receiver that has a support arm protruding outward from the front surface of the dish. The support arm supports a low noise block amplifier with an integrated feed “LNBF”. The dish collects and focuses the satellite signal onto the LNBF which is connected, via cable, to the subscriber's set top box.
To obtain an optimum signal, the antenna must be installed such that the centerline axis of the dish, also known as the “bore site” or “pointing axis”, is accurately aligned with the satellite. To align an antenna with a particular satellite, the installer must be provided with accurate positioning information for that particular satellite. For example, the installer must know the proper azimuth and elevation settings for the antenna. The azimuth setting is the compass direction that the antenna should be pointed relative to magnetic north. The elevation setting is the angle between the Earth and the satellite above the horizon. Many companies provide installers with alignment information that is specific to the geographical area in which the antenna is to be installed.
The ability to quickly and accurately align the centerline axis of antenna with a satellite is somewhat dependent upon the type of mounting arrangement employed to support the antenna and the skill of the installer. Prior antenna mounting arrangements typically comprise a mounting bracket that is directly affixed to the rear surface of the dish. The mounting bracket is then attached to a vertically oriented mast that is buried in the earth, mounted to a tree, or mounted to a portion of the subscriber's residence or place of business. The mast is installed such that it is plumb (i.e., relatively perpendicular to the horizon). Thereafter, the installer must orient the antenna to the proper azimuth and elevation. These adjustments are typically made at the mounting bracket.
In an effort to automate the adjustment and positioning of an antenna, several different permanent motorized antenna mounts have been designed. For example, U.S. Pat. No. 4,726,259 to Idler, U.S. Pat. No. 4,626,864 to Micklethwaite, and U.S. Pat. No. 5,469,182 to Chaffe disclose different motorized antenna positioners that are designed to be permanently affixed to an antenna. Those devices are not designed such that they can be used to orient an antenna and then removed therefrom in order that they can be used to orient another antenna.
Thus, there is a need for a portable antenna alignment device that can be attached to antenna to automatically position the antenna in a desired orientation and removed therefrom to enable the device to be used to position other antennas.